Switch to UTF-8 for Strings

[Rob Eden]

String encoding currently uses UTF-16 and should be replaced with UTF-8. Obviously, backwards compatibility will need to be handled.

[Rob Eden]

This will be done in protocol version 3

[Rob Eden]

Switch to UTF-8 for string encoding, remove ResourceKey usage.

The persistent name in Invoke message is now encoded with UTF-8 rather than UTF-16 (proto >= 3).

The "reason" fields in ChannelInitResponse and SessionClose are now encoded with UTF-8 strings rather than serialized ResourceKeys (proto >= 3).

No exceptions now extend Localized(Runtime)Exception. The common-locale library is no longer used except for compatibility with protocol versions <3 and so have been changed to an optional dependency.

Fixes: #12 Relates to: #16

→ <<cset 785d39df51d6>>